• Amtrak - Operates the Amtrak passenger trains, most trains stop and start at the Santa Fe Depot, then go north. Amtrak also stores trains at the freight yard south of downtown.

• Bayside tracks - The "heavy rail" tracks west and south - used by Coaster, Amtrak, BNSF.

• Cityside tracks - The trolley "light rail" tracks on the north and east side of the rail right-of-way.

• CCDC - Centre City Development Corporation. Public, non-profit corporation that operates on behalf of the City of San Diego Redevelopment Agency for downtown San Diego. Overseeing the Quiet Zone project, www.ccdc.com  see Downtown Quiet Zone under "Projects".

• City of San Diego - Will be required to sign legal agreements necessary to create the Quiet Zone, and agree to pay maintenance and additional insurance costs. Legal agreements with MTS, NCTD, BNSF.

• CPUC - California Public Utilities Commission - A state agency responsible for all work in the railroad right-of-way. The Quiet Zone project will get an Order (permit) from the CPUC for all rail work and affecting work in the railroad right-of-way.

• Final Rule - Federal Government legislation for Use of Locomotive Horns at Highway - Rail crossings that also contains the requirements to establish a Quiet Zone. Became law June 25, 2005. Can be read at the FRA website - http://www.fra.dot.gov/us/content/1318

• Final Rule Diagnostic Team - Required to review all the grade crossings in a Quiet Zone. Consisted of the FRA, NCTD, CPUC, MTS, BNSF, Amtrak, City of San Diego, CCDC and CCDC rail consultants to review the field conditions of each crossing in the Quiet Zone to determine the needed safety enhancements. Review completed in 2005 for San Diego Quiet Zone.

• FRA - Federal Railroad Administration - responsible for Quiet Zone law, train horn sounding and enforcement of law.

• MTS - Metropolitan Transit System - local transportation agency. Owns the railroad right-of-way, tracks and trolley signal system for the Quiet Zone crossings on the Cityside of the rail the trolley tracks. Also owns the heavy rail right-of-way E Street and north - ѕ of Quiet Zone.

• NCTD - North County Transit District - maintains the heavy rail Bayside of tracks and signal systems E Street and north. Runs the Coaster trains. Will design and construct the north part of the Quiet Zone (Broadway and north) for both NCTD and MTS trolley side, paid for by CCDC.